Bill, I am puzzled why a bad EL5146C would cause an INFO 080 problem. INFO 080 normally is the inability of the MCU to properly communicate with another firmware processor. While it is entirely possible that the EL5146C was dragging down the output of the +5v regulator and causing the KPA100 firmware IC to fault, but I cannot tell from this distance.
As for your wattmeter problems, I suspect that the diodes D16 and D17 may be "half bad". Yes, that is rare, but possible - they have been damaged enough to change their characteristics but not make them either open or shorted. I would recommend arbitrarily replacing them and then try the wattmeter calibration again. For initial settings, adjust R26 to produce 43k ohms to ground as measured at U5 pin 5, and R27 to give 43k ohms as measured at U5 pin 3. After that do the null adjustment and see what happens. I just returned from the Shelby, NC hamfest - a good time was had by all even though it was quite hot and humid. 73, Don W3FPR On 9/1/2012 4:31 PM, Bill Coleman wrote: > My KPA100 has been giving good service for nine and a half years. Back in > July, it was giving me an INFO 080 issue, which I tracked down to a defective > U6 - EL5146C on the KPA100. I've successfully replaced this chip, and now the > KPA100 is responding. > > Because of the part replacements, I have gone through the KPA100 alignment > steps. The first indication of a problem was during the SWR Bridge Null > Adjustment. While I could get a clear null, the display never showed anything > less than 1.1 SWR on 40m. > > Next the Power Calibration. This went fine as well, but when I checked the > SWR on all the bands, I received a 1.8 SWR on 80m, and 2.6 on 160m. The > highest bands gave a 1.0 indication, but most of the others were 1.1, just > like 40m. > > I double-checked my dummy load with my external watt meter. It appears they > are 1.0 on all bands. > > Doing some full-power tests: > > * 40m - K2 indicates about 70 watts (7 bars), but the external watt meter > shows 100 watts > * 80/160m - K2 indicates about 50 watts (5 bars), and sometimes I get a Hi > Cur warning. The external watt meter shows 100 watts, or perhaps a little > more. > > Something is obviously wrong with the power measurement circuits here. Any > suggestions as to what I should do to troubleshoot this further? > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
